Mobile cranes, i.e. cranes supported on vehicles, must be provided with support legs preventing the vehicle from tipping over during the crane loading operations. In constructing support legs and the jibs therefor it is necessary to consider
A. the maximum vehicle width permissible PA1 B. that when the support leg jib is fully extracted a not unimportant portion of its total length must rest in the crane base cross beam in order that the stress on the load-bearing parts remain at the permitted values, and PA1 C. that when the jib sections are formed so as to be telescopically displaceable relative to one another it is normally necessary that the inner jib beam is formed with a support shoulder against which the outer jib beam abuts whereby its displacement into the crane base is interrupted, for which reason this latter jib beam cannot be made as long as the crane base cross beam would otherwise permit, could its entire length have been utilized.